Mac OS X Leopard only: Despite its unfortunate name, task manager Anxiety is a slick, good-looking, lightweight way to keep track of your to-do lists. Since Leopard now includes a “calendar store,” or central repository of tasks from both iCal and Mail.app, Anxiety taps into those lists and displays the items on your desktop. Add, change or check off a to-do in Anxiety, iCal or Mail? And the info updates across all three applications. Neat. Anxiety is a free download (donations encouraged) for Mac OS X Leopard only.